To prevent explosive combustion in combustible liquids or gases in receptacles, e.g. fuel tanks, it is already known to provide the tank during its manufacture with a filler in the form of a body of expanded metal composed of thin aluminum foil. The disadvantage of incorporating a block of the expanded aluminum foil in a fuel receptable or tank, however, is that the dimensions of the expanded metal body make it difficult to remove the body even with deformation and distortion thereof or make it impossible to remove the body from the tank. Such a removal of the filler from the tank may become necessary or desirable for cleaning of the tank or for repair thereof.
In addition, it has been impossible to introduce conventional tank-filler bodies of expanded metal into already fabricated fuel tanks or receptacles, also because of the dimensional factors mentioned previously.